This application proposes to establish a fourth Mutant Mouse Regional Resource Center (MMRRC) repository at The Jackson Laboratory (JAX). For over 60 years mutant mice, with phenotypes mimicking human diseases, have played a critical role in understanding the genetics underlying mammalian biology and human genetic disorders. The advent of transgenic and gene targeting technologies, coupled with large scale mutagenesis and gene trap programs has led to a virtual explosion in the production and use of mutant and genetically engineered mice. These valuable resources can only be fully exploited if they are archived, managed, and made accessible to the scientific community by centralized repositories. The Jackson Laboratory's experience and capacity as a repository, the quality of its existing programs, its management systems, and its reputation for research excellence all demonstrate that JAX will be a strong addition to the MMRRC network. In this application, we propose to establish a JAX MMRRC that would: 1) acquire mutant strains; 2) import and archive mutant strains; 3) distribute strains as cryopreserved material, mice recovered from cryopreserved material, ES cell lines, or live mice; 4) implement a state-of-the-art quality control program; 5) provide customer support and technical service; 6) promote MMRRC strains; 7) have an interactive Repository management plan; 8) establish the bioinformatics infrastructure to operate and to interact with other MMRRC repositories, and 9) conduct research to add utility to JAX MMRRC strains by developing pluripotent stem cell resources from valuable Repository disease models using both standard derivation techniques and IPS technology. The JAX MMRRC will be fully functional upon funding and will offer experience and capacity to the existing MMRRC program.